Device for continuous adjustment of spectrometer gap widths

ABSTRACT

A microscope has an aperture arrangement that, in order to limit the dimension of a light beam, comprises an aperture opening. The size of the aperture opening is adjustable with the aid of a first aperture member and a second aperture member. At least one of the two aperture members is movable relative to the other aperture member. The aperture members are spaced apart from one another when the aperture opening is closed.

RELATED APPLICATIONS

This Application is a Continuation Application of U.S. patentapplication Ser. No. 13/753,161 filed on Jan. 29, 2013, which in turn isa Continuation Application of International ApplicationPCT/EP2011/060695, filed on Jun. 27, 2011, which in turn claims priorityto German Patent Applications No. 10 2010 036 790.7, filed on Aug. 2,2010, all of which are incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The invention relates to a microscope having an aperture arrangement.The aperture arrangement comprises an aperture opening in order to limitthe dimension of a light beam. The size of the aperture opening isadjustable with the aid of a first aperture member and a second aperturemember. At least one of the two aperture members is movable relative tothe other aperture member.

Aperture arrangements are often arranged within a microscope. Theaperture arrangements serve to limit, in a radial direction,illumination light beams or detection light beams that extend in anaxial direction. The aperture openings are, for example, slit-shaped,circular, or polygonal. Very small aperture openings, for example in theregion of nanometers, can be generated with the aid of the aperturearrangement. With such small aperture openings the risk often existsthat the aperture members which define the aperture openings will bumpinto one another, as a result of an irregularity in the application ofcontrol by positioning elements for adjusting the aperture members or asa result of production tolerances, and thus be damaged. This isproblematic in particular when the aperture members are additionallyequipped with reflective surfaces, since these can easily be damaged.The reflective surfaces serve, for example, to reflect the blocked-outportions of the light, for example to a further aperture arrangement orto an additional detector.

BACKGROUND OF THE INVENTION

DE 103 19 776 A1 discloses an apparatus for spectral selection anddetection of the spectral regions of a light beam. The selection deviceencompasses means for spectral dispersion of the light beam, and meansfor blocking out a spectral region and for reflecting at least theblocked-out spectral region.

DE 199 02 624 A1 discloses an optical arrangement for spectral spreadingof a light beam. The arrangement is arranged in the detection beam pathof a confocal microscope. The light beam is focused onto a pinhole thathas a polygonal passage.

DE 43 30 347 A discloses an apparatus for selecting and detecting twospectral regions of a light beam. The apparatus encompasses a selectiondevice that has means for spectral dispersion of the light beam andmeans for blocking out a spectral region and reflecting the blocked-outspectral region.

SUMMARY OF THE INVENTION

The object of the present invention is to create a microscope that hasan aperture arrangement with which very small aperture openings can begenerated in a particularly reliable manner.

The object is achieved by the features of the independent claim 1.Advantageous embodiments are indicated in the dependent claims.

The invention is notable for the fact that the aperture members arespaced apart from one another when the aperture opening is closed. Thefact that the aperture opening is closed means in this connection thatno portion of the light beam is passing through the aperture opening,and the aperture arrangement is thus completely occluding the lightbeam.

The result of the fact that the aperture members are spaced apart fromone another when the aperture opening is closed is that the aperturemembers can be brought arbitrarily close to one another as the apertureopening becomes smaller, and the aperture opening can thus be madearbitrarily small. If the aperture members should happen, as a result ofirregular control application or because of production tolerances, to bebrought so close to one another that they overlap when viewed in thepropagation direction of the light beam, they nevertheless do not bumpinto one another, thereby avoiding damage to the aperture members. Theaperture opening can be, for example, circular, slit-shaped, orpolygonal.

In an advantageous embodiment, the two aperture members are arrangedwith an offset from one another in the axial direction of the light beamto be limited. This allows particularly simple implementation of thefact that the aperture members are spaced apart from one another whenthe aperture opening is closed. Alternatively or additionally, onlyaperture edges of the aperture members can be arranged, when theaperture opening is closed, with an offset from one another in the axialdirection of the light beam to be limited. This allows the aperturemembers to be arranged at the same height in an axial direction, butnevertheless allows a spacing between the aperture members to beimplemented when the aperture opening is closed.

In order for the aperture opening to be closable, at least one of theaperture members is movable in a direction almost perpendicular, orperpendicular, to a beam axis of the light beam to be limited.Alternatively or additionally, one of the aperture members can berotatable around a rotation axis that is almost parallel, or parallel,to the beam axis of the light beam to be limited. Alternatively oradditionally, at least one of the aperture members is swingable around aswing axis that is almost perpendicular, or perpendicular, to the beamaxis of the light beam to be limited.

One of the embodiments of the invention comprises a microscope having anaperture arrangement that, in order to limit a dimension of a firstportion of a detection beam, comprises an aperture opening whose size isadjustable with the aid of a first aperture member and a second aperturemember, at least one of the aperture members being movable relative tothe other aperture member, and one side of the aperture memberscomprising a reflective region that reflects a second portion of thedetection beam such that the first portion of the detection beam passesthrough the aperture opening, wherein the aperture members are spacedapart from one another when the aperture opening is closed and whereinthe first portion has a first wavelength and the second portion has asecond wavelength different from the first wavelength.

In a further embodiment of the invention, the aperture arrangement ispart of a spectrometer that is arranged in the microscope. The aperturearrangement can be arranged, for example, in a detection beam path ofthe microscope. The microscope can be embodied as a laser microscope, asa confocal microscope, as a fluorescence microscope, multiphotonmicroscope, and/or as a scanning microscope.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplifying embodiments of the invention are explained in furtherdetail below with reference to schematic drawings, in which:

FIG. 1 shows a microscope,

FIG. 2 shows a first embodiment of an aperture arrangement with theaperture opening opened,

FIG. 3 shows the first embodiment of the aperture arrangement with theaperture opening closed,

FIG. 4 shows a second embodiment of the aperture arrangement with theaperture opening opened,

FIG. 5 shows the second embodiment of the aperture arrangement with theaperture opening closed,

FIG. 6 shows a third embodiment of the aperture arrangement with theaperture opening opened,

FIG. 7 shows the third embodiment of the aperture arrangement with theaperture opening closed.

Elements of identical design or function are labeled, throughout theFigures, with the same reference characters.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a microscope 10 having a spectrometer 11 and having a lightsource 12. Microscope 10 is a confocal laser microscope. Light source 12is accordingly a laser that generates laser light at one, two, or morewavelengths, or with a continuous wavelength spectrum. In particular,light source 12 generates an illumination light beam 14 that is directedvia a main beam splitter 16 and an objective 18 onto a sample that isarranged on a sample stage 20. Detection light proceeding from thesample passes through objective 18 and main beam splitter 16 toward aprism 24, in which context main beam splitter 16 separates a detectionlight beam 22 from illumination light beam 14. Prism 24 splits detectionlight beam 22 in accordance with wavelengths. In particular, at leastone light beam 26 having a first wavelength and one light beam 28 havinga second wavelength emerge from prism 24.

Light beam 26 of the first wavelength is limited, in its dimensionperpendicular to its axial extension direction, with the aid of anaperture arrangement 29. Aperture arrangement 29 encompasses a firstaperture member 32 and a second aperture member 34. The two aperturemembers 32, 34 define an aperture opening 37 through which a portion offirst light beam 26 of first wavelength passes and is detected with theaid of a first detector 30. The two aperture members 32, 34 eachcomprise a reflective region 33, 35. Reflective regions 33, 35 serve toreflect light of wavelengths different from the first wavelength. Inparticular, light beam 28 of the second wavelength is reflected byreflective region 35 of second aperture member 34, so that a reflectedlight beam 36 strikes a second detector 38 and is detected there.

Alternatively or additionally, microscope 10 can comprise a scanningunit. Microscope 10 can moreover operate in a non-confocal manner. Inparticular, microscope 10 can acquire sample images using thetransmitted light method. Microscope 10 can furthermore comprise manymore aperture arrangements 29 so that light beams 26, 28 of differentwavelengths can be distributed onto many more detectors, so that lightbeams 26, 28 of multiple different wavelengths are simultaneouslydetectable independently of one another.

In addition to the optical elements shown, such as e.g. aperture members32, 34, further optical elements (not depicted for reasons of clarity)can preferably also be arranged, in particular further apertures oraperture members, pinholes, or lenses. In particular, for example, alens can be arranged respectively between aperture members 32, 34 andfirst detector 30 and/or between main beam splitter 16 and prism 24.

FIG. 2 shows a first embodiment of aperture arrangement 29. A light beam41 to be limited is directed, in the direction of reflective regions 33,35, onto the two aperture members 32, 34. Light beam 41 to be limitedproceeds along a beam axis 42. The light passes through aperture opening37. The aperture opening is limited by the two aperture members 32, 34,in particular by a first aperture edge 39 of first aperture member 32and by a second aperture edge 43 of second aperture member 34. A limitedlight beam 40 extends beyond aperture opening 37.

The size of aperture opening 37 is modifiable by adjusting the twoaperture members. In particular, with the aid of a positioning element(not depicted), first aperture member 32 is movable in a first motiondirection 44 and second aperture member 34 is movable in a second motiondirection 46 perpendicular to beam axis 42. As long as limited lightbeam 40 passes through aperture opening 37, aperture opening 37 isreferred to as “opened.”

FIG. 3 shows the first embodiment of aperture arrangement 29 withaperture opening 37 closed. The fact that aperture opening 37 is“closed” means in this connection that no portion of light beam 41 to belimited passes through aperture opening 37. In other words, whenaperture opening 37 is closed, aperture members 32, 34 are moved farenough toward one another that they overlap from the point of view oflight beam 41 to be limited, so that light beam 41 can no longer passthrough aperture opening 37. When aperture opening 37 is closed, the twoaperture members 32, 34 are spaced apart from one another. This allowsthe two aperture members 32, 34 to slide so close to one another thataperture opening 37 can be arbitrarily small, and extends over only afew nanometers. If the two aperture members 32, 34 are moved evenfurther toward one another as a result of production tolerances orirregular control application, a clearance then nevertheless existsbefore they bump into one another and might be damaged.

FIG. 4 shows a second embodiment of aperture arrangement 29 in which thetwo aperture members 32, 34 are rotatable. For this, first aperturemember 32 is secured on a second mount 47 and second aperture member 34is secured on a first mount 45. The two mounts 45, 47 are respectivelyrotatable in a first rotation direction 48 around a first rotation axis49, and in a second rotation direction 50 around a second rotation axis51. Aperture members 32, 34 are mounted eccentrically on mounts 45, 47,so that the size of aperture opening 37 can be varied by rotating theaperture members 32, 34. Aperture opening 37 is opened, so that lightbeam 41 to be limited passes at least in part through aperture opening37, and limited light beam 40 propagates further beyond the apertureopening.

FIG. 5 shows the second embodiment of aperture arrangement 29 withaperture opening 37 in the closed state. In this exemplifying embodimentas well, the two aperture members 32, 34 are arranged with an offsetfrom one another in the axial direction of beam axis 42. The result ofthis is once again that aperture members 32, 34 can make apertureopening 37 arbitrarily small without bumping into one another. In theclosed position, no portion of light beam 41 to be limited passesthrough aperture opening 37.

FIG. 6 shows a third embodiment of aperture arrangement 29 with apertureopening 37 opened. In this embodiment, first aperture member 32 isswingable or pivotable around a second swing axis 62, and secondaperture member 34 is rotatable or swingable around a first swing axis60. The two swing axes 60, 62 preferably extend perpendicular to beamaxis 42. The two aperture members 32, 34 are swung out far enough thataperture opening 37 is opened, and light beam 41 to be limited passes atleast in part through aperture opening 37 in the form of limited lightbeam 40.

FIG. 7 shows the third embodiment of aperture arrangement 29 withaperture opening 37 closed. When aperture opening 37 is closed, onceagain no portion of light beam 41 to be limited passes through apertureopening 37, since aperture members 32, 34 are swung close to oneanother. The two aperture members 32, 34 are swung with respect to oneanother in such a way that aperture edges 39, 34 [sic: ?43] are arrangedwith an offset from one another in the axial direction of light beam 42to be limited, so that despite production tolerances or an irregularapplication of control by positioning elements for adjusting a size ofaperture opening 37 in the nanometer region, the two aperture members32, 34 do not bump into one another and are thus spaced apart from eachother when aperture opening 37 is closed.

The invention is not restricted to the exemplifying embodimentsindicated. For example, instead of or in addition to prism 34, anotheror a further spectrally dispersing element can be provided. Theindividual exemplifying embodiments can furthermore be combined with oneanother. For example, one of the two aperture members 32, 34 can berotatable or swingable, and the other of the two aperture members 32, 34can be shiftable perpendicular to beam axis 42. Furthermore, one of thetwo aperture members 32, 34 can be swingable and the other rotatable.Moreover, for each aperture arrangement 29 one of the sides of aperturemembers 32, 34 can be reflective.

The size of aperture opening 37 can be adjusted, for example, with theaid of a software program stored on a control device. The software canbe used interactively by way of a computer. The two detectors 30, 38, oroptionally further detectors, can be read out with the aid of thesoftware. Aperture openings 37 of aperture arrangements 29 associatedwith these detectors can moreover be adjusted individually.

PARTS LIST

-   10 Microscope-   11 Spectrometer-   12 Light source-   14 Illumination light beam-   16 Main beam splitter-   18 Objective-   20 Sample stage-   22 Detection light beam-   24 Prism-   26 Light beam of first wavelength-   28 Light beam of second wavelength-   29 Aperture arrangement-   30 First detector-   32 First aperture member-   33 Reflective region of first aperture member-   34 Second aperture member-   35 Reflective region of second aperture member-   36 Reflected light beam-   37 Aperture opening-   38 Second detector-   39 First aperture edge-   40 Limited light beam-   41 Light beam to be limited-   42 Beam axis-   43 Second aperture edge-   44 First motion direction-   45 First mount-   46 Second motion direction-   47 Second mount-   48 First rotation direction-   49 First rotation axis-   50 Second rotation direction-   51 Second rotation axis-   60 First swing axis-   62 Second swing axis

What is claimed is:
 1. A microscope having an aperture arrangement that,in order to limit the dimension of a light beam, comprises an apertureopening whose size is adjustable with the aid of a first aperture memberand a second aperture member, at least one of the two aperture membersbeing movable relative to the other aperture member, wherein theaperture members are spaced apart from one another such that theaperture members do not get in contact with each other when the apertureopening is closed.
 2. The microscope according to claim 1, in which thetwo aperture members are arranged with an offset from one another in theaxial direction of the light beam to be limited.
 3. The microscopeaccording to claim 1, in which, when the aperture opening is closed,aperture edges of the aperture members are arranged with an offset fromone another in the axial direction of the light beam to be limited. 4.The microscope according to claim 1, in which one side of at least oneof the aperture members comprises a reflective region that reflects aportion of the light beam, such that another portion of the light beampasses through the aperture opening.
 5. The microscope according toclaim 1, in which, for adjustment of the size of the aperture opening,at least one of the aperture members is movable in a direction almostperpendicular, or perpendicular, to a beam axis of the light beam to belimited.
 6. The microscope according to claim 1, in which, foradjustment of the size of the aperture opening, at least one of theaperture members s rotatable around a rotation axis that is almostparallel, or parallel, to a beam axis of the light beam to be limited.7. The microscope according to claim 1, in which, for adjustment of thesize of the aperture opening, at least one of the aperture members isswingable around a swing axis that is almost perpendicular, orperpendicular, to a beam axis of the light beam to be limited.
 8. Themicroscope according to claim 1, which comprises a spectrometer thatencompasses the aperture arrangement.
 9. The microscope according toclaim 1, in which the aperture arrangement is arranged in a detectionbeam path of the microscope.
 10. The microscope according to claim 1, inwhich at least one of the aperture members is embodied in circular,round, polygonal, quadrangular, rectangular, or square fashion.
 11. Themicroscope according to claim 1, which is embodied as a lasermicroscope, as a confocal microscope, as a fluorescence microscope,multiphoton microscope, and/or as a scanning microscope.